Quantitative fetomaternal hemorrhage assessment with the use of five laboratory tests.

INTRODUCTION: In various countries, standard doses of anti-D IgG used for postpartum immunoprophylaxis of hemolytic disease of fetus and newborn (HDFN) vary from 100 µg to 300 µg. There are also different regulations concerning FMH assessment, and opinions about applicable tests are inconclusive. METHODS: Three flow cytometry tests (FCTs) with anti-D, anti-HbF, anti-HbF+CA antibodies, and two modifications of microscopic Kleihauer-Betke test (KBT) were used. RESULTS: In all artificial mixtures with known concentrations, FCTs and KBT with counting 10 000 RBCs had similar satisfying sensitivity and specificity. KBT with counting 2000 RBCs had to be disqualified because of significant discrepancies between expected and measured values of FMH. The test procedure with anti-D was easier and shorter than the remaining tests, but it can be only used for FMH assessment in RhD-negative mothers with RhD-positive newborns. In one clinical sample, it was impossible to distinguish fetal RBCs from maternal F cells in KBT and FC with anti-HbF but other tests were useful. CONCLUSION: In the four tests, correlation between expected and obtained results was appropriate (CCC Ì´1). Each test had some advantage and limitation in any clinical situation. Therefore, it is best to have opportunity to perform two or three assays in the laboratory.

Assessment of feto-maternal hemorrhage among rhesus D negative pregnant mothers using the kleihauer-betke test (KBT) and flow cytometry (FCM) in Addis Ababa, Ethiopia.

BACKGROUND: This study aimed to assess fetomaternal hemorrhage (FMH) among RhD negative pregnant mothers using two techniques, Kleihauer-Betke (KBT) and Flow cytometry (FCM). To determine if patient-specific doses of prophylactic anti-D warrant further investigation in Ethiopia and wider Africa. METHODS: Hospital- based cross-sectional study was conducted among 75 RhD negative pregnant mothers using convenient sampling technique. RESULT: FMH has been detected in 52% and 60% by KBT and FCM techniques, respectively. The volume of FMH quantified in the majority of the cases (92.5% and 87%) was <10 mL fetal blood while >30 mL in 1.3% (1/75) and 2.7% (2/75) as calculated by KBT and FCM, respectively. The FMH calculated by the two methods have good correlation; r = 0.828 (p = 0.000) for categorized and r = 0.897 (p = 0.000) for continuous values and the agreement between the FCM and KBT was moderate with kappa (κ) value of 0.53 (p = 0.000). CONCLUSION: Most of FMH calculated (<10 mL) could have been neutralized by lower doses which might have lower costs than administering 300 µg dose which is currently in practice in our country for affording mothers. Besides, it also showed that the volume of FMH was >30 mL in 1.3% and 2.7% of the cases as calculated by KBT and FCM, respectively, which need more than 300 µg dose RhIG for neutralization. Further investigation into the cost- effectiveness and scalability of patient- specific dosing of prophylactic anti-D appears warranted.

Assessment of fetomaternal hemorrhage by Kleihauer-Betke test, flow cytometry and α-fetoprotein after invasive obstetric procedures.

PURPOSE: The aim of this study was to evaluate the passage of fetal red blood cells to the maternal circulation, after invasive obstetric procedures, through the Kleihauer-Betke test, flow cytometry and by measurement of maternal serum alpha-fetoprotein level. METHODS: This prospective descriptive study with patients submitted to amniocentesis, cordocentesis, chorionic villus sampling (CVS), amnioreduction and ventriculoamniotic shunt was performed for karyotype analysis, treatment of hydrocephalus and polyhydramnios and to assess fetal lung maturity. Maternal blood samples were collected before and 60 minutes after the invasive obstetric procedure to search for fetal erythrocytes using the Kleihauer-Betke test, flow cytometry and serum alpha-fetoprotein measurement. RESULTS: Ten invasive obstetric procedures were performed. The mean age of the patients was 29.2 years and the mean gestational age was 29.6 weeks. The procedures were: five amniocenteses, two cordocenteses, one CVS, one ventriculo-amniotic shunt and one amnioreduction with cephalocentesis. The indications for the procedures were: karyotype analysis in five patients, fetal lung maturity assessment in two patients, amnioreduction in one patient, fetal hydrocephalus shunt in one patient and polyhydramnios related to hydranencephaly in one patient. Regarding the path of puncture, three procedures were accomplished through the placenta and seven apart from it. All punctures were successful at the first attempt. There was no significant increase of fetal erythrocyte quantity in maternal blood samples using the Kleihauer-Betke test. After cordocentesis, a significant increase of fetal erythrocytes was detected by flow cytometry and serum alpha-fetoprotein measurement. CONCLUSION: Invasive obstetric procedures during prenatal care are safe when performed by experienced professionals using adequate techniques, with minimal chance of passage of fetal erythrocytes from the fetal compartment.

The assessment of feto-maternal hemorrhage in an artificial model using anti-D and anti-fetal hemoglobin antibody by flow cytometry.

BACKGROUND: When fetal red cells enter the maternal circulation from placenta, an event would be happened that is described as feto-maternal hemorrhage (FMH). This life-threatening condition could be detected by using RBC antigens (surface antigens and intracellular antigens). Therefore, the measurement of fetal RBC in an artificial model would be useful to calculate FMH and consequently the dosage of Rhogam for prophylaxis. The aim of the present study was to evaluate FMH in an artificial mixture model. METHODS: A series of 40 artificial specimens were prepared consisting of Rh(D) negative adult blood (non-immunized) spiked with varying amounts of Rh(D) positive cord blood from mothers between 20-30 years old in Shahid Beheshti Hospital, Tehran, Iran. Monoclonal anti-D and anti-HbF (fetal hemoglobin) were used for detection of fetal RBC in artificial mixture sample modeling. RESULTS: This study showed that the percentage of fetal cells in artificial sample for anti-D antigen is in ranges of 0.28%-0.32% for a 0.25% dilution mixture, and 1.3%-2.05% for the mixture with dilution 2%. In addition, the ranges of data for anti-HbF staining was obtained 0.2%-0.34% for the 0.25% dilution sample, and the ranges of 1.04-1.8% for the 2% dilution. The regression analysis indicated that the correlation of anti-D assessment with expected standard method was r2 = 0.9672 and anti-HbF assessment was r2 = 0.8842. CONCLUSION: Although both molecule targets could be used for detection of fetal RBC, in this model, anti-D staining was more accurate than anti-HbF staining. However, since anti-D can not be utilized for low-density or weak phenotype and other incompatibility, the anti-HbF labeling could be used for all FMH.

Assessment of fetomaternal hemorrhage by flow cytometry and Kleihauer-Betke test in Rh-negative pregnancies.

OBJECTIVES: To assess the efficacy of flow cytometry (FC) in the detection and quantification of fetomaternal hemorrhage (FMH) in comparison to the Kleihauer-Betke test (KBT). METHODS: 25 unsensitized Rh-negative mothers who had delivered Rh-positive infants were included. Presence of FMH was determined by KBT and FC using FITC-labeled BRAD-3 antibodies. RESULTS: FMH was detected in 19 (76%) patients by FC and 23 (92%) patients by KBT prior to delivery, and in 21 (84%) patients by FC and 23 (92%) patients by KBT after delivery. The mean volume of FMH in the post-delivery samples by KBT and FC were 0.34 +/- 0.26 ml (range 0.05-1.2 ml) and 0.37 +/- 0.57 ml (range 0.02-2.6 ml) respectively. The volume of post-delivery FMH estimated by KBT and FC correlated well (r = 0.75; ICC alpha = 0.73). A higher agreement between KBT and FC was seen in the 0.1-0.5 ml range (kappa = 0.65; p < 0.01). CONCLUSIONS: Both manual KBT and FC using FITC-BRAD-3 antibodies show good sensitivity in detecting and quantifying fetal red cells. There is a good correlation between the methods in the 0.1- to 0.5-ml range of FMH.

Flow cytometric assessment of feto-maternal hemorrhage; a comparison with Betke-Kleihauer.

OBJECTIVES: Assessing the number of fetal cells in the maternal circulation quantifies the volume of feto-maternal hemorrhage, enhancing the ability to provide effective prevention of Rhesus (Rh) allommunization and appropriate fetal surveillance in cases of significant feto-maternal hemorrhage. METHODS: Having developed a standard curve with maternal samples spiked with known volumes of fetal red blood cells, we used a flow cytometric method using fluorescent labeled antihemoglobin F to quantitate fetal cells in the maternal circulatory system in two groups of women undergoing chorionic villus sampling (CVS), by either biopsy forceps or cannula aspiration (n = 170 women). We compared these results with the gold standard, the Betke-Kleihauer test. RESULTS: Our results show good correlation between the flow cytometric method and the traditional Betke-Kleihauer method for fetal red cell quantitation (r(2) = 0.99). Fetal red blood cells were identified in 10 women by the Betke-Kleihauer method, and in 26 women by flow cytometry. CVS was not associated with an increase in feto-maternal hemorrhage. CONCLUSION: Flow cytometry was both more sensitive and more timely for the quantitation of feto-maternal hemorrhage than was Betke-Kleihauer.

The issue of anti-D: an integrated seamless approach from recognition of need to bedside administration.

BACKGROUND: The appropriate and timely administration of Anti-D immunoglobulin to Rhesus (D) negative women who have delivered Rhesus (D) positive babies is a vital part of obstetric care. Anti-D has an especially high profile in Ireland because of the tragic inadvertent transmission of Hepatitis C to Irish women in past decades. AUDIT: We have reviewed our policy and procedures pertaining to the administration of Anti-D for sensitising events during pregnancy and postnatally, in the Mid-Western Health Board in 1999/2000. As a result, major changes were made in the storage, issue, recording and administration of Anti-D. New procedures in the transfusion laboratory and in the maternity hospital have been accepted by scientists and midwives and supported by haematology and obstetric medical staff. The pharmacy and haematology laboratory no longer have a role in this programme. IMPLEMENTATION OF MULTI-DISCIPLINARY CHANGE MANAGEMENT: As a result of these changes, the storage, issuing and tracking of Anti-D has become the responsibility of the hospital blood bank. Measurement offoeto-maternal haemorrhage (FMH) is now the responsibility of bio medical scientists in blood bank, utilising both flow cytometry (increasingly recognised as the gold standard method) and the Kleihauer method (Kleihauer-Betke). The programme has moved from a doctor-administered IV Anti-D Ig, to a midwife-administered IM preparation. Prescription remains the responsibility of the doctor. These changes are facilitated by the protocol guided issue of the appropriate dose of Anti-D Ig by bio medical scientists to midwives. The issue of the Anti-D Ig occurs simultaneously with issue of results of mother and baby's serology testing and estimation of volume of FMH. These major changes have been guided by audit and needs assessment and require close liaison between medical, nursing and laboratory scientific staff in haematology, transfusion and obstetrics. CRITICAL INCIDENT AUDIT-CASE REPORT: Before new procedures became official policy, a critical incident audit allowed us to pilot our protocol and to revise it using draft new procedures. In this critical incident we describe successful management of a patient with a large foeto-maternal haemorrhage. This incident supported the need for the procedural enhancements already underway. This critical incident re-emphasised the need for the planned systems improvements to be introduced quickly.

Assessment of fetal-maternal haemorrhage in mothers with hereditary persistence of fetal haemoglobin.

Kleihauer examination of peripheral blood cannot be used reliably to detect transplacental fetal-maternal haemorrhage in mothers with hereditary persistence of fetal haemoglobin (HPFH). In Rh(D) negative pregnancies diagnostic confusion with a large fetal-maternal haemorrhage could result in the administration of inappropriately excessive amounts of anti-D immunoglobulin, and the inability to diagnose and quantify transplacental haemorrhage in maternal HPFH by current methods could result in insufficient anti-D administration and subsequent Rh(D) sensitisation. Accordingly, a method to detect and quantify fetal-Rh(D) positive maternal haemorrhage using erythrocyte fluorescent immunocytometry was developed. An indirect immunofluorescence method with IgG anti-D immunoglobulin as the primary antibody was used, combined with quantitative analysis on a fluorescence activated cell sorter. The method was accurate, specific, and sensitive and could detect a contaminating population of 0.1% Rh(D) positive cells in Rh(D) negative blood--a level of fetal-maternal haemorrhage well covered by a single dose of 500 IU of anti-D immunoglobulin.

[Ante-partum administration of preventive treatment of Rh-D immunization in rhesus-negative women. Parallel evaluation of transplacental passage of fetal blood cells. Results of a multicenter study carried out in the Paris region]. / Application anté-partum du traitement préventif d'immunisation rhésus D chez les femmes rhésus négatif. Evaluation parallèle des passages transplacentaires d'hématies foetales. Résultats d'une étude multicentrique menée en région parisienne.

1,969 non immunized rhesus negative primiparous women were followed up in 23 maternity units in the geographical region of Paris. 1,882 could be retained to study antepartum protection and 1,884 to study transplacental passage of fetal blood cells. Two groups were defined according to whether they were born in even or uneven years, so that: 955 were the "control" group who delivered 590 rhesus D positive infants, and 927 were the "treated" group who delivered 599 rhesus D positive infants. The "control" group were used as controls at the 28th and 34th weeks of pregnancy, while the "treated" group received two injections of anti-D immunoglobulin given on the same dates after taking the necessary tests. Immunological testing at the time of the delivery and after the delivery showed that 7 women had become Rh D immunized in the "control" group whereas only one in the "treated" group. This difference, which is statistically significant, confirms the results of other authors about the efficiency of antepartum rhesus disease prevention. The incidence of immunisation during or immediately after the first pregnancy in women who had no previous story of blood transfusions or of terminations of pregnancy is 1.11%, which is a figure relatively low as compared with studies of series carried out in North America, but close to those carried out in other European centres. When primipara of all categories are lumped together the frequency rises to 1.5%. A study of the passage of fetal red blood cells into the maternal circulation shows that at the 29th week of pregnancy out of 1,884 cases there were 5.5% positive kleihauer tests, without a large volume of blood being detected and at the 34th week of pregnancy when 957 tests were carried out, 7% were positive with one of them being of a massive transfusion of blood from the fetus to the mother, which was life-threatening for the fetus. It may be that the incidence had been under-estimated and that the positive results in the two groups, control and treated, show that there is a statistically significant difference that demonstrates that antepartum treatment in the trial has eliminated a worthwhile percentage of positive kleihauer tests which arose from the transfusion of small quantities of blood.(ABSTRACT TRUNCATED AT 400 WORDS)

The assessment of fetal-maternal hemorrhage by an enzyme-linked antiglobulin test for Rh immune globulin recipients.

An enzyme-linked antiglobulin test has been developed to detect and quantitate fetal-maternal hemorrhage. The test is applicable to postpartum screening of Rh immune globulin candidates. The enzyme-linked antiglobulin test has greater sensitivity than agglutination tests; it has fewer false positive results than acid-elution detection methods and offers advantages for use in routine clinical laboratories. Postpartum samples from 186 mother were assessed by the enzyme-linked antiglobulin test; only 20 samples (10.75%) has detectable fetal cells, and no patient had bleeding of more than the limit of 30 ml of whole blood for one vial of Rh immune globulin. No clinical or historic factors could predict the patient at high risk for fetal-maternal hemorrhage. The use of the enzyme-linked antiglobulin test also could permit the reduction of the postnatal Rh immune globulin dosage and salvage much of the Rh immune globulin now administered.

Assessment of size of small volume feto-maternal bleeds. A new method of quantification of the Kleihauer technique.

The risk of Rh-isoimmunization is probably related to the volume of foeto-maternal bleeding. With the Kleihauer technique foetal cells may be detected in maternal blood, but estimation of the size of foetal bleed the cells represent is at present difficult and open to serious error.A new method of quantifying the technique by using a standard volume of maternal blood, and a simple machine for the preparation of comparable blood films, is described. The new method eliminates many of the errors of previous techniques, and should be capable of automation for large-scale screening programmes.